Alternator output and power demand of all electrical loads and systems must be matched to each other as ideally as possible so that the entire system is reliable and trouble-free in operation. The ECM monitors alternator output deviation from the signal of the FR terminal of the alternator when the engine is running.
ECM sets DTC P0625 if the ECM detects that the alternator's output duty signal is 100%.
Item
Detecting Condition
Possible Cause
DTC Strategy
Input signal check
Short to Ground in harness
Poor connection or damaged harness
Enable Conditions
Engine start after keeping ignition ON more than 2 sec.
Threshold Value
Duty calculated by Alternator PWM signal = 100%
Diagnostic Time
3 sec.
MIL ON Condition
DTC only
Fig.1) Idle Status
Fig.2) Electrical Load (Head Lamp and Defrost are ON
Duty(+) from FR terminal is increased if electrical loads are ON(Head Lamp and Defrost are ON) ECM controls generation of alternator with duty from FR terminal when electrical Loads turn on